The present invention relates to a valve-closing mechanism for an inclined valve.
At present, in a Y-shaped automatic ball valve as shown in FIG. 1, the valve is driven by a pneumatic cylinder (b) with a leading valve (a). The mounting attitudes include two types, one in which the valve shaft is perpendicular to a horizontal pipe as shown in FIG. 2B, hereinafter referred to as an "Upright valve", and the other in which the shaft is inclined 15.degree. from the perpendicular (FIG. 2C, hereinafter referred to as an "Inclined valve". Both of these valves are designed so that when the valve is opened or closed, a poppet (c) is guided by ribs (e) formed on the internal surface of a body (d). Normally, three ribs (e) are provided at locations as shown in FIG. 3. Because of which the poppet (c) becomes eccentric at its axis with respect to the axis of the body (d) due to its own weight. This is one of causes of impairing the good operation of the Y-shaped automatic ball valve. Particularly, in the aforementioned inclined valve, the poppet (c) falls between the ribs (e), and the amount of such fall is added to the amount of eccentricity (1/2 of the difference between the inside diameter of the body (d) and the outside diameter of the poppet (c)) of the upright valve, thereby giving rise to a greater eccentricity. Especially, in the event that deterioration such as an increase in frictional resistance of the valve seat portion occurs during use, smooth aligning of the poppet is impossible to obtain, and therefore, an improvement thereof has long been desired.